The present invention relates to means for connecting a patient to an anesthesia or ventilating machine, and more specifically to a double-lumen tube adaptor which permits such connection while providing advantages not heretofor attainable.
Once a patient is fitted with a double-lumen or two passageway tube, the connection between the double-lumen tube and the anesthesia machine or ventilator is typically made through an adaptor referred to as a double-lumen tube adaptor. Detailed study and investigation of previously designed double-lumen tube adaptors has revealed the tremendous need for a simple adaptor allowing conventional ventilation of both lungs with several desired features:
(1) The ability to ventilate each lung independently; PA0 (2) The ability to expose one lung to atmospheric pressure; PA0 (3) The ability to suction each lung independently; PA0 (4) The ability to sigh each lung independently; PA0 (5) The ability to perform fiberoptic bronchoscopy on each lung independently. PA0 (6) The ability to apply one-lung PEEP (Positive End-Expiratory Pressure) or CPAP, with or without tidal ventilation; PA0 (7) The ability to apply differential PEEP to both lungs; PA0 (8) The ability to deliver simultaneous independent lung ventilation.
At the same time modern respiratory therapy implies the need for a second simple adaptor allowing several additional features:
While the first five features are obtainable with a double-lumen tube adaptor of a first type having only a single or common machine-side entry port (that is, a machine-side port connecting with but a single anesthesia machine or ventilator), the last three features (in addition to the first five) are obtainable only with a second type of double-lumen tube adaptor, one having two independent machine-side entry ports (that is, separate machine-side entry ports for connection to separate anesthesia or ventilating machines).
The prior art double-lumen tube adaptors of both types have not proven entirely satisfactory in use. For example, their design is typically so complex as to require airway disconnection or clamping, interruption of ventilation, or the use of unreliable mechanical elements to enable switching from one feature to another. In particular, the complexity of the design of the adaptor having a machine-side common entry port (type one) described in Yamamura T., "A Single-Unit Device For Differential Lung Ventilation with only one anesthesia machine." Anesthesia and Analgesia, 64:1017-20 (1985), is so complex as to require internally both stopcocks and a one-way valve. The adaptor with two machine-side entry ports (for two anesthesia machines or ventilators) (type two) described in Andersen H. W., "A New Improved Double-Lumen Tube Adaptor," Anesthesiology, 56:54-56 (1982) similarly requires the use of unreliable stopcocks.
Accordingly, it is an object of the present invention to provide a double-lumen tube adaptor having all of the requisite features of its type (as described above) and affording use of all of these features without airway disconnection or clamping, interruption of ventilation, or the use of unreliable mechanical elements.
It is another object to provide such an adaptor having a high degree of reliability in use through the absence therefrom of valves, stopcocks and other inherently unreliable mechanical elements.
A further object is to provide such an adaptor which is economical to manufacture and maintain due to its simplified design.